The present invention relates to power hand tools and, more particularly, to a portable power saw having a self-contained engine.
Battery powered portable tools have long been known in the art and have proved useful in regard to such devices as wrenches, screwdrivers, and jigsaws. Such battery-power tools are not suitable for high power construction tools.
Similarly, certain large pieces of equipment and, most notably, portable chain saws, have long been equipped with internal combustion engines to permit one working in the outdoors to operate the saw without need for a portable electric generator. Such prior art, as best known to the inventor, is represented by U.S. Pat. No. 2,697,457 (1954) to Lawrence, entitled Manually Portable Brush Cutting Power Tool; No. 2,698,034 (1954) to entitled Portable Chainsaw with Detachable guards; No. 3,346,955 (1967) to entitled Tree and Hedge Trimmer; No. 4,179,805 (1979) to entitled Portable Power Operated Tool; and No. 4,696-108 (1987) to entitled Pruning Apparatus.
Many other examples of equipment intended for outdoor use in areas removed from electric availability show the use of an internal cumbustion engine as a power means. However, no prior art known to the inventor makes use of an internal combustion, or gas, engine in integral combination with a hand held power saw of the type that is widely used by builders and handymen in construction and related work.
The need for such a device has been long felt in the art in that it, heretofore, has been necessary to employ a long electrical extension cord from a hand-held power saw to electrical outlet or, alternatively, to a portable electrical generator, in order to power the hand held portable saw. This, understandably, resulted in considerable inconvenience and, in the case of work done on ladders or at elevations above the one ground, must contend at all times with the location, positioning and potential change in position in the extension cord. It is, for example, not uncommon for an electrical extension cord to a portable hand held powered saw to become entangled in the feet of the user, the ladder or blade of the power saw.
It is, therefore, in response to the above problem in the art that the instant invention is directed.